| 摘要 |
PURPOSE:To prevent magnetic flux as a signal indcating that a heating element is in operation from leaking upto the upper surface of a top plate by a method wherein a magnetic shielding plate is arranged within the table at the titled device capable of indicating the power-on state of the heating element of the electric ''kotatsu'' at the top plate surface. CONSTITUTION:In the electric ''kotatsu'', the heating element 4 is heated by turning-on a source switch 3 and at this time, magnetic flux 15 is generated in an iron core 2, because an exciting coil 2a is simultaneously energized by said turning-on of the source switch 3. The top plate 7 placed through a coverlet 6 on the ''kotatsu'' consists in equipping at its center with a detecting coil iron core 8 and a detecting coil 8a, which receive said magnetic flux 15. Transistors 9 and 10 are turned on by means of AC voltage generated in the detecting coil 8a in order to emit light from a light emitting diode element 12 with the power of a cell 14 so as to indicate that the heating element 4 is in operation. Furthermore, the magnetic shielding plate 16 is arranged above the iron core 8 within the table 7 in order to prevent the magnetic flux 15 from leaking upto the upper surface of the top plate 7. |
